Grease gun



June 8 1926. 1,587,597

W. J. Ma'CLELLAN GREASE GUN Filed March 15, .1926 2 Sheets-Sheet 1 J Mclelam June 8 1926. 1,587,597

v w. J. MacLl-:LLAN

GREASE GUN Filed March l5, 1926 2 Sheets-Sheet 2 Patented June 8, 1,926.

UNITED STATES PATENT OFFICE.

WILLIAM J'. MAGLELLAN, 0F LONG BEACH, CALIFORNIA, ASSIGNOB OF ONE-FOURTH TO HIMSELF, ONE-FOURTH TO G. W. FOURNIER, ONE-FOURTH T WILLIAM M. LAND, AND ONE-FOURTH T0 JOSEPH H. ROGERS.

GREASE GUN.

' Application led March 15, 1926. Serial No. 94,819.

An object of this invention is to provide a simple.V practical grease gun of*V the spring pressed piston type that is compact and that is alternatively operable automatically or by hand. that may be brought into collapsed condition for storage and transportation, and in which the piston can be locked at any point in the primary pump barrel.

The invention is applicable in different sizes for various uses; for forcing grease into bearings of automobiles and other machinery.

Another object is to provide novel'means for locking and unlocking the piston rod relative to the pump barrel.

This invention relates to that class of grease guns having a container; a booster head detachably connected thereto and closing one end; a spring operated piston head in the container arranged to automatically force grease into the booster head. Such grease guns may be filled by removing the booster head and forcing the grease into the open end of the container while the spring operated piston head is retracted by means of a handle.

It is dicult to completely charge the container so that there will be no air ockets in the charge or in the container, w ich may 80 interfere with the automatic discharge of grease from the container into the booster head; and an object of this invention is to eliminate this difliculty and insure the proper discharge of grease into the booster head.

The invention includes the parts and coinbinations of parts hereinafter more particularly described and claimed.

This invention is broadly new, basic and pioneer in that I employ a piston head, and

y a piston rod for operating the same, which rod is adapted to be attached to and detached from the piston head; and l also provide means whereby the piston rod may be detachably fixed to the container so that the piston rod may be unshipped from the piston head and mainly chambered in the con tainer when it is desired to make the grease gun compact; and also provide means whereby the piston rod may be held in fixed relation to the container and to the piston head when it is desired to hold the head from yielding to the pressure of the spring. An object is to make provision whereby,

invention may appear from the accompany- Ving drawings, the subjoined detailed description and the appended claims. The accompanying drawings illustrate the invention.

Figure 1 is a fraginental longitudinal section ot' a grease gun constructed in accordance with this invention, with the parts in position for automatic action; the container and booster head being charged with grease. The position of the booster head lever when the booster head is closed is indicated in broken lines.

Fig. 2 is an elevation partly in section of the grease gun shown in Fig. 1 free from any charge with the booster head closed and the piston down.

Fig. 3 is an elevation partly in section .showing the parts locked in position retracting the piston head.

Fig. 4 is a plan of Fig. 1 in section on line w, Figs. 1, 2 and 3.

Fig. 5 is an enlarged section on line Figs. 1, 2 and 3.

Fig. 6 is an enlarged end view of the lock stop nut detached.

Fig. 7 is a longitudinal section of the lock stop nut on line m7, Fig. 6.

Fig. 8 is a plan view of the piston head end plate shown in section at the bottom of Fig. 9.

Fig. 9 is a dis-assembled view of the parts of the piston head.

Fig. 10 is an inside View of the felt packing box without packing.

Fig. 11 is a view of the spacing cup.

Fig. 12 is a face view of the bayonet slot cover.

Fig. 13 is an inside view of the leather cup washer.

The container 1 is a pump barrel externally screw threaded at its ends to receive the cap 2 and to screw into the booster head 3.

4 is the piston head comprising the felt packing box 5, felt bushing 6, spacing cup 7, bayonet slot cover 8, the leather cup 105 washer 9, and the end plate 10.

'rho cap 2 is provided `with an externally threaded nipple '11 having fan .inwardly tapering'scat 12 foithe tapered end 13 of (he split bushing formed of two picces 14 vcontained within the cap nut 15 having an internally threaded portion 16 that screws on the nipple 11 to force the bushing 14 to clamp thev piston rod 17, Which extends through the cap nut 15, bushing 14 andthe' nipple 11 into the barrel 1 and through the to catch on said bayonet slot cover 8 WhentheV piston rod 17 is turned to bring the pin 18 into parallelism with the slot 20, which is of suflicient length to allow the pin 18 to pass therethrough when alinedtherewith.

The diameters of the holes 21, 22 of the leather cup Washer 9 and end cap 10 are, 4sufficient to allow through such holes the pin to pass freely so 'that by yturning the piston rod into the appropriate position relative to the piston head, the piston rod can be pushed through the piston head and leave the piston head -free to be operated by the l spring 23 in the usual manner.

The piston rod is made non-rotatable relav` tive to the cap nut so that when the pis-` ton rod is rotated it will turn the cap nut. This result is attained in the form shown, by providing the piston rod with a flat side 211 and the cap nut with a hole 25 conforming peripherally with the periphery of the piston rod so that when `the iston rod is rotated by its handle 26,it Will rotate thel cap nut 15 in one direction to screw the cap i nut onto-the nipple and thereby cause the vbushing 14 to be brought to the piston rod to prevent en tionof the rod in the container; and when ether to clamp such rod is turned in the other direction, they cap nut will be unscrewed and release the bushing `14: from clamping position.

The bore of the cap nut is suificiently long relative to the nipple andbushings, to al- Vlovv the nut to be screwed a considerable distance4 onto the .nipple before the bushings are forced into clamping position so that there is considerable freedom of rotation of the piston rod after the cap nut is vcaught on the nipple and before-the bush- Vandthe handle 2.6 is drawn ings are brought into clamping position.

In practice the parts are `assembled as shown in Fig. 2 andthe piston rod rotated to bring the pin transverse to the `slot 20;-

back to compress the spring as shown in Fig. 3. The booster head 8 being unscrewed, the operator may lill the container and then screw the booster Wise reciprocal turned ,to loosen the vclamping oflthe bushings 14 and may then be shoved ldown into position shown in Fig. 1, leaving the spring 23 free to act on'the free piston head, to force grease into the .booster head.

The felt washer 6 prevents the grease from being squeezed out through the packing box. The booster plunger 27 may then be operated by its handle 28 to force the grease in the cylinder 29 of the booster head out of the booster head. In case there are air pockets, not .`sh0rwnn the grease in the container, and thc piston. headhas been forceddown until the pocket comes to the duct 30 in thebooster head the force of the spring is not suiicient to overcome the cushion formed by the air pocket. The operator may then'draw the handle 26 and the sliding piston rod out until the pin engages the bayonet slot cover 2O and then turn the handle to bring the pin into position to pass through such slot and to further turn in the chamber 3l of the piston head, 'so that by pushing the handle back, the piston head can be forced toward the booster head,"thus positively forcingv out the air when the plunger 27 is drawn back.

In this way cushioning air bubbles, not shown, may be forced out through the booster hea 32 yindicates bolts which hold the' end plates 10 against the cup and hold the felt packing box, the spacing cup, and the bayonet slot cover together.

I claim: i

1. A grease gun comprising a container, a piston head operable in the container and a piston rodrotatable relative to the piston head and adapted to be thereby attached to and detached from the piston head; and means operableby rotatingV the piston rod to clampthe piston rod to the container.

2.1,A grease gun comprising in combination a container, apiston head in the container, a piston yrod for `operating the head, said piston rod being adapted to be rotated and also to be moved cndwise; and clamping means operable by the rotation .of the `bushing and ,means operated by the piston rod to clamp the bushing on the pistonfrod.- 4. The combination with acontainer having a'threaded nipple, ofy a rod extending through the nipple, a. nut screwed onto lthe nipple; said rod being slidable through the nut and non-rotatable relative thereto; and a bushing inside the nut adapted to be wedged together V'when the nut is screwed liome,fthus to-clamp the bushing against the rod to prevent' the rod from longitudinal movement relative tothe nipple.

1 *15. The combinationv with the piston head having achamber and a piston rod having relative to the p'n adapted to the chamber when be moved into and out of the rod is in one position head and adapted to move the head When the rod is in another position relative to the piston head; a packing box'cap on the piston head Aand packing in said packing box.

6. The combination with a piston rod of a pistonV head comprisinganwend plate, aV

' a packing in the box,

cup`.vvasher on the end plate, a bayonet slot cover, a .spacing cup, a packing box, means to secure the plate, the packing box and the cup washer together, and a pin on said piston rod adapted to pass through the bayonet slot when turned to one position and to be stopped by the bayonet slot cover when turned to another position.

In testimony whereof, I have hereunto set my hand `at Los Angeles, California, this 10th day of March, 1926.

Y WILLIAM J. MACLELLAN. 

